DMF 

I found a box of (unthreaded) CO2 cartridges for air guns. I don't see anything on the box about oil or other additives. Are these okay to use for bike tube inflators?

well biked

I use the bb gun cartridges exclusively when I inflate with C02, the bicycle-labeled CO2 is a good example of merchandise labeled specifically for bicycles being somewhat inflated (no pun intended ) in price. They'll work fine, you can find them at X Mart in the bb gun section for very cheap-

DMF 

Figures. I asked the question at my LBS and got some drivel about how you need something like medical grade CO2 for bike tubes or you'll get a chemical reaction...

redirekib

Medical grade CO2.....I needed a good laugh

seriouslysilly

medical grade?!?
for what other purpose would those bike-advertised C02 cartridges supposed to be used for?


the only reaction i can foresee is from elitist as they make a comment from their italian bikes that it's not from Park tool while you get your motobecane up and going again

Al1943

They'll be fine but threaded are better for road bikes because of the higher pressure.

KevinF

Medical grade CO2??? Now *that* is beautiful! I use CO2 inflators myself; I've often heard that CO2 leaks out of tubes faster then regular air does. Can anyone confirm / deny? What reason would there be for this?

HillRider

That's nonsense too. A 12 gm cartridge holds 12 gms of CO2 at exactly the same pressure whether it's threaded or not. The liquid/gas inside doesn't know or care what the outside of the container looks like and the tire doesn't either.

Same comment applies to 16 gm cartridges except 16 gm unthreaded cartridges aren't as commonly available.

Portis

The biggest problem with the 12 g cartridges is that they don't inflate enough for me.

HillRider

I use a mini-pump to bring the tire (700 x 23) up to about 20 - 30 psi so I'm sure the tire is seated properly and the new tube is good. Then I give it an entire 12 gm CO2 cartridge and that gets me 100+ psi which is plenty to continue my ride.

A larger tire will of course require more CO2 but the 16 gm cartridges, particularly the threaded ones, are SO expensive that using two 12 gm threadless cartridges is still much cheaper.

Rev.Chuck

A CO2 molecule is larger than an O2 molecule so(in theory) the leakage should be less, but I am just a drivel spouting bikeshop person*.(I did ask a chemist)

And for whover posted it, a proper Italian bike rider would never stoop to use a Park tool, all their tools come straight out of the Campagnolo tool kit.



*Bashing on LBS is the reason that very few industry people post here any more. There was a mass exodus of industry and shop people about a year and half ago. They realised how little they were appreciated on this forum and split.

ax0n

Ah, but our atmosphere isn't pure O2, or even MOSTLY O2. Lots of nitrogen.

Who cares if CO2 leaks out a little faster... I don't know if it does, but CO2 is for emergencies. You should always use your floor pump (with a gauge) before every outing.

See my review of the CO2 system I currently use, for more info and the results I've seen:
https://kc-bike.blogspot.com/2007/05/...novations.html

And yes, I use BB gun carts for mine, and never had a problem.

HillRider

Yes, CO2 does leak out faster than an oxygen/nitrogen mix (aka air) despite the fact it has a higher molecular weight than either major component of air. Apparently, the solubility of CO2 is greater in rubber than air is so it difuses through faster than pure permeability would suggest.

CO2 lasts long enough to get you through any ride but the tire should be refilled or topped up with air as soon as convenient.

DMF 

No bashing here.

Still, when such drivel as cited above is spouted, it's hard to resist the temptation.


Btw, is it true that your handle is an abbreviation of "Reversible Chuck"?

noisebeam

I've been dismayed that the non-bike 12g carts don't get my 700x25c tire to 110-120psi.
But I never considered that two 12g non-bike carts still cost less than one 16g bike marketed one.

I think having two (actually would carry four) 12g is better as I find I am giving them away faster than I use them.
Another benefit is one can use one 12g and know if tire if fixed, if not one can still use the 2nd one and have enough pressure to finish a ride.

Al

lopsided

CO2 is used in medicine for such things as insufflators for laparoscopic procedures (tubals, hernia repairs, cholecystectomies-gall bladder removal) but, as far as I know, the tanks that hold these gases get filled at the same company that the weldors, beverage vendors and anyone else with a need for CO2 (or oxygen) get their tanks filled. Medical grade?? Sounds like BS to me.

Portis

Threadless 16 g cartridges are dirt cheap on ebay. I bought a whole bunch of them last year and have tons of them left.

DMF 

So what's a good inflator to use with these? The one I have takes threaded. (And I usually carry a frame pump so lighter and smaller is better.)

slowandsteady

I just bought a bunch of the airgun 12g threadless CO2 cartridges at Walmart for cheap. But I am having a problem with them. I can't seem to get them into the Inflator...the head of the cartridge just won't puncture. What am I doing wrong? I don't recall having any issues with the CO2 that came with the inflator.

Bill Kapaun

Well, you are somewhat ignorant.
At least some gases are available in more "purified" grades.
I used to build optical oceanographic instruments and we purchased a "higher grade" of nitrogen (less moisture) for purging the internals. Regular "welding grade" probably would have been sufficient, but for the price of our instruments,($3k-10k each) it made more sense to pay a couple more bucks per bottle.